FIG. 4 is a schematic diagram of a conventional induction heating device. The heating device includes top plate 22, infrared sensor 23, temperature detector 24, heating coil 25, controller 26, and input section 27. On top plate 22, cooking utensil 21 is placed. Infrared sensor 23 is disposed to face a lateral side of cooking utensil 21. Temperature detector 24 converts the light energy received by infrared sensor 23 into temperature. Coil 25 is disposed under top plate 22. Controller 26 controls coil 25 to induce a high-frequency current so as to induction-heat cooking utensil 21. Input section 27 receives input from a user, which is sent to controller 26 as heating conditions.
When the user operates input section 27 to start to heat cooking utensil 21, coil 25 generates a high-frequency magnetic field in response to a signal from controller 26. This high-frequency magnetic field heats cooking utensil 21 to increase its temperature. Infrared sensor 23 detects the intensity of the infrared radiation from cooking utensil 21, and temperature detector 24 converts the output of infrared sensor 23 into temperature. Controller 26 controls the amount of heating based on the conversion result.
In this structure, infrared sensor 23 is disposed above top plate 22 in order to measure the temperature of the lateral side of cooking utensil 21. This, however, causes infrared sensor 23 to receive the infrared radiation from not only cooking utensil 21 but also other sources, decreasing the accuracy of the temperature measured by temperature detector 24.
Patent Document 1: Japanese Patent Unexamined Publication No. 2006-294284.